This invention relates to the production of N-aliphatic substituted p-phenylenediamine intermediates. In one aspect, this invention relates to the production of N-aliphatic substituted p-phenylenediamines. In another aspect, this invention relates to the production of N'-alkylated, N-aliphatic substituted p-phenylenediamines useful as antioxidants or antiozonants.
It is known to prepare dialkyl substituted p-phenylenediamines by the reaction of a p-halonitrobenzene with ammonia to produce p-nitroaniline followed by reductive alkylation of the p-nitroaniline. This process involves a nucleophilic aromatic substitution mechanism wherein the ammonia replaces halide to produce the p-nitroaniline. This process is disadvantageous in that the halide that is displaced is corrosive to the reactors and appears in the waste stream and must therefore be disposed of at considerable expense. Therefore, a nonhalide route to N-aliphatic substituted p-phenylenediamines and the alkylated products thereof would provide significant advantages over current technology and result in a more efficient and economic commercial process.
The process of the invention is such a nonhalide route to N-aliphatic substituted p-phenylenediamines and the alkylated products thereof and therefore eliminates the expensive halide removal from the waste stream as well as corrosion problems caused by the halide.